Not applicable.
Not applicable.
The invention relates to a device for laminating a substrate onto an adhesive-coated substrate for forming a laminate, in which the substrate provided with adhesive is supplied to a laminating point formed between a driven roller and a laminating roller, and to a device for coating at least one layer onto a substrate for producing a coated length of material in which the substrate coated with the at least one layer is supplied to a laminating point formed between a driven roller and a laminating roller.
Devices have already become known in which a substrate is laminated onto a first layer coated with adhesive for forming a laminate. For this purpose, a driven roller and a laminating roller are provided, which are spaced apart to form a gap, a laminating point being formed by the gap. The adhesive-coated layer is guided, e.g., horizontally through the gap, so that this layer lies on the laminating roller and the driven roller only in the laminating point. The laminate is guided away after the laminating point by removal from the driven roller and the laminating roller. The same analogously holds for the coated length of material.
Such devices are used for the production of laminates and lengths of material for various end uses. For example, there can be concerned here, air-permeable or breathable textiles, and full-surface, partial, or porous coatings. Also, substrates of different thickness, stiffness and weight per m2 are laminated or coated.
The above-described device has the disadvantage, particularly when laminating two different substrates, in which one substrate is, e.g., heavier than the other, that the laminate comes apart after leaving the laminating point, since the adhesive has not yet completely set in order to bind the substrates firmly together. In particular, with a further roller arranged remote from the laminating point, the laminate can sag, due to which, in particular, the heavier substrate can detach from the lighter substrate. The circumstances are similar for coated lengths of material.
The invention therefore has as its object to provide a device for the production of a laminate with at least two substrates, or a coated length of material, which makes a firm laminate bond or coating possible, particularly with different substrates or layers, even with large amounts of adhesive.
This object is attained according to the invention by a device for laminating at least one substrate (32) to a substrate (18) provided with adhesive (19) for the formation of a laminate (36), in which the substrate (18) provided with adhesive is supplied to a laminating point (29) formed between a driven roller (16) and a laminating roller (31), the at least one substrate (32) being supplied by means of the laminating roller (31) to the substrate (18) provided with adhesive (19) and bonded to the substrate (18) provided with the adhesive in a laminating point (29), wherein the laminate (36) formed from the substrates (18, 32), at least one substrate provided with adhesive is guided directly after the laminating point (29) at least through a plurality of angular degrees along the laminating roller (31), and the laminating roller (31) comprises a temperature-adjustable roller.
The object is also attained by a device for coating at least one layer (15) onto a substrate (18) for the production of a coated length of material (39), in which the substrate (18) coated with the at least one layer (15) is supplied to a laminating point (29) formed between a driven roller (16) and a laminating roller (31), wherein the length of material (39) formed from the at least one layer (15) and the substrate (18) is guided directly after the laminating point (29) at least through a plurality of angular degrees along the laminating roller (31), and that the laminating roller (31) comprises a temperature-adjustable roller.
By the laminate lying at least over a few degrees of angle on a laminating roller and a simultaneously occurring adjusted temperature, particularly cooling, of the laminate, it is made possible for the adhesive to be transformed from a plastic to a solid state and for a firm bond between two laminated substrates to be constituted. By the resting of the two substrates, laminated together, on the laminating roller, the substrate layers are simultaneously pressed against an envelope surface of the laminating roller between the laminating point and the takeoff of the laminate from the laminating roller, so that a bonding of the substrates under at least a little pressure is made possible due to the tension of the length of material. By the constitution of the laminating roller as a temperature-adjusted roller, an increased amount of heat of the heated adhesive and the heat of reaction of the adhesive when setting can be conducted away at least sufficiently. Thereby it is achieved that the laminated substrate is removed from the laminating roller only after the adhesive has solidified, so that a finished laminate is drawn off from the laminating roller.
This similarly holds for the production of coated lengths of material. Here the at least one layer is firmly bonded to the substrate. The advantages and effects are the same in the production of coated length of material as in the production of the above-described laminate.
It is advantageously provided that the laminate after passing through the lamination point is guided along the laminating roller with a wrap angle of at least 45xc2x0, preferably at least 180xc2x0. It is thereby made possible for the laminate to rest on the laminating roller for a long period and for a sufficient heat removal to be ensured, so that the adhesive has transformed from a viscous or pasty state at least into an adherent and solid state which holds the two substrates together in the laminate, before removal of the laminate from the laminating roller. Furthermore, pressing together of the substrates due to the material tension is attained for a longer dwell time by means of an increased wrap angle.
An embodiment provides that the laminating roller constituted as a cooling roller has at least twice the diameter of the driven roller. By this design, it can furthermore be attained that, e.g., in addition to increasing the wrap angle of the laminate, the path length up to removal from the laminating roller is made greater. Because of the greater diameter of the laminating roller, no delay arises in the working process itself, but the degree of setting of the adhesive considerably increases.
According to a further embodiment, it is provided that the driven roller is preceded by a metering roller and an application roller, and the adhesive is applied to the application roller by the metering roller and is transferred to the substrate carried along on the driven roller. By means of this multi-roller system, a metered adhesive application to the substrate can take place, the substrate preferably being guided through, and the adhesive being applied, between the application roller and the driven roller. The amount of adhesive being applied can be specifically set by means of this multi-roller system. For example, adhesive layers of 5-950 g/m2 can be applied, independently of the roller length. Alternatively to the multi-roller system, sprinkler coating systems or wide slit nozzles can also be used.
By the variable setting of the circumferential speed of the application roller and of the driven roller, it is made possible for the adhesive film present on the application roller to be once more varied in its thickness. For example, a thinner adhesive film can be applied to the substrate than that supplied by the application roller to the application point. At the same time, e.g. in the application of the adhesive to a fabric with a coarser structure, complete impregnation of this fabric can be attained. Substrates with larger depressions on the application side can be coated with adhesive so that these recesses or niches are completely filled with adhesive. In other cases of application it can be attained that an extremely thin layer is applied to the substrate and complete wetting just does not occur, for forming a porous coating, for example. The amount of application of the adhesive film can be application-specifically determined by means of the size of the adjustable gap between the application roller and the driven roller and/or the relative circumferential speed of the two rollers. For example, the circumferential speeds of the application roller and of the driven roller can be adjustable in a ratio of 2:1 or higher.
It is provided that the substrate supplied to the driven roller passes through a heating station before the application of adhesive takes place. A rapid cooling of the adhesive is thereby prevented. Better wetting can occur of substrates with a very uneven or porous surface. In support, it can also be provided that the driven roller can be heated. Likewise, the driven metering roller and the application roller can be heated. The adhesive thus remains viscous, or is at least plastic, in the laminating point, and has the required adhesive properties.
At least one tensioning roller is provided before the driven roller, and supplies the substrate under tension to the driven roller. In this manner, on the one hand the tension of the length of material is regulated or maintained, and on the other hand it is made possible for the substrate to be passed through with a defined course between the application roller and the driven roller, so that also the amount of adhesive application is adjustable.
It is provided that the tensioning roller is arranged to be displaceable relative to the application roller, so that the substrate has a wrap angle to the application roller before reaching the gap between the application roller and the driven roller. The degree of wrap is adjustable by positioning the tensioning roller. By means of the substrate lying in contact over a given amount of the circumference of the application roller, a longer dwell time between the substrate and the adhesive is given, so that better impregnation of the material is attained. In a gap formed between the application roller and the driven roller, the adhesive film is adjusted to the predetermined layer thickness or to the predetermined application weight per m2.
For forming a firm bond between the two substrates forming a laminate, at least one presser roller is provided on the outer circumference of the laminating roller. This can give an after-pressing of the laminate, so that in addition to positioning the two substrates to one another, a further setting of the adhesive can also be effected.
The laminating roller can be adjusted in its spacing from the driven roller.
Thus both a setting to different substrate thicknesses can take place and also a pressing together of individual components of the substrate, in order to form the desired product. For example, the thickness of the adhesive layer between a fabric and a non-woven fabric or a foam layer laminated onto it can be determined.
The laminating roller constituted as a cooling roller has a double jacket design, in which a duct system for the cooling liquid running in the opposite direction is preferably provided. Temperature equalization over the circumference of the laminating roller can thereby be given, so that an amount of heat can be removed at a constant rate. Water is preferably provided as the cooling liquid. Additional coolants such as Glysantin or the like can likewise be added.
The previously mentioned advantages and advantageous embodiments likewise hold for the layer applied to the substrate for the production of a coated length of material.
The present invention is particularly provided for the application of so-called hot melt adhesives, high power adhesives, or adhesives with additives and/or fillers, and having a melting point above 50xc2x0 C. These adhesives, such as for example thermoplastic adhesives or polymers, thermoplastic resins or reactive adhesives, are suitable for complete or partial coating or for laminating of various substrates such as textiles, fabrics, knitted fabrics, paper, films, and foils. The use of such hot melt adhesives makes possible good processing based on their high viscosity, high productivity based on satisfactory coating at high material speeds, and also because of their environmentally friendly handling.
In the production of coated lengths of material, besides the above-mentioned adhesives, open or closed pore foam layers, non-woven fabric layers, non-woven fabric layers or combinations thereof can also be used. Thus different backcoated starting, intermediate, or finished products can be produced.
For example, for substrates which receive loop pile fabric, cut pile fabric, or filaments, the application of a layer as an adhesive layer or foam layer is sufficient to fix the loops, pile, or filaments to the substrate. There can be mentioned only as examples of this the production of furnishing fabrics, decorative fabrics, knit fleeces, mattress drills or the like. By the contact of the coated substrate with the laminating roller and the presence of a compressing pressure, the loop or cut pile fabrics or filaments can be held and fixed in a desired position with respect to the substrate after passing through the laminating point.